1. Field of the Invention
The present invention relates to a magnetic disk module adapted to be inserted in a data storing device body which is in use.
2. Description of the Related Art
A typical magnetic disk device used as an external data storing device for a computer comprises a cabinet defining a plurality of shelves, and magnetic disk modules accommodated in the shelves. The magnetic disk module comprises a disk drive unit, accommodating magnetic disks and a head assembly, a printed wiring board controlling the disk drive unit, a power supply unit, and a housing to accommodate these components.
A connector is arranged at the rear of the housing to make a plug-in connection to a mating connector the shelf when the magnetic disk module is inserted into the cabinet shelf. The entire magnetic disk module can be removed from the cabinet shelf to replace the disk drive unit, the printed wiring board or other parts. Such a cabinet and a magnetic disk module are disclosed, for example, in Japanese Unexamined Patent Publications (Kokai) No. 4-275095, No. 4-214288 and No. 4-259980.
With the recent tendency to increase the size of computer systems, magnetic disk devices are required to have larger capacity, while the size of the device is required to be smaller. To satisfy such contradictory requirements, a magnetic disk module having two disk drive units and two printed wiring boards for controlling the disk drive units, in the one housing, has been proposed. For example, it is possible to construct a magnetic disk module containing two sets of 5 inch magnetic disk drives and printed wiring boards, such that the magnetic disk module is the same size as the conventional magnetic disk module containing one 8 inch magnetic disk drive and one printed wiring board. The magnetic disk module having two 5 inch magnetic disk drives can be used in the conventional magnetic disk device, and can satisfy the requirement for a larger capacity without increasing the size of the device.
In addition, it is also required to reduce the time necessary for the replacement or the repair of a disk drive unit or a printed wiring board for controlling the former, in order to minimize the effect of a failure on the operation of the computer system. In the conventional magnetic disk module, the entire magnetic disk module is removed from the cabinet shelf when the replacement or repair of the disk drive unit or the printed wiring board is necessary.
In the magnetic disk module having two sets of disk drive units and printed boards for controlling the units in one housing, supposing that one of the disk drive units or printed boards is abnormal but the other disk drive unit or printed board is normal, it is possible to minimize the effect on operation of the computer system if the abnormal unit is detachable from the housing while keeping the other operative, compared with the case in which both sets must be detached from the housing. However, in the conventional magnetic disk module, the disk drive unit and its controlling printed wiring board are fixed to the housing by screws and connected to connectors at the power supply unit and the rear end of the case, respectively, through cables, so it is difficult to remove the disk drive unit and its controlling printed wiring board from the housing and the above requirement is not be satisfied.
SUMMARY OF THE INVENTION
An object of the invention is to provide a magnetic disk module in which a disk drive unit or a printed wiring board can be easily attached to or detached from a housing thereof.
Another object of the present invention is to provide a magnetic disk module having a plurality of sets of disk drive units and printed wiring boards.
A further object of the present invention is to provide a magnetic disk module including two sets of disk drive units and printed boards in which one disk drive unit or printed board can be easily detached, while keeping the other disk drive unit and printed wiring board in the operative condition.
A still further object of the present invention is to provide a magnetic disk module including cooling fans having a reliable cooling performance.
A still further object of the present invention is to provide a printed wiring board assembly which can be used for a magnetic disk module or the like and has an additional printed wiring boards with terminals projecting from the outer surface thereof.
According to the present invention, there is provided a magnetic disk module adapted to be inserted in a data storing device body in use, said module comprising: a housing having a front end and a rear end; at least one disk drive unit accommodated in the housing and having a first connector; at least one printed wiring board accommodated in the housing for controlling the at least one disk drive unit and having a second connector; a power supply unit accommodated in the housing; a third connector arranged at the rear end of the housing for plug-in connection to a connector of a data storing device body when the magnetic disk module is inserted into the data storing device body; a fourth connector arranged in the housing for plug-in connection to the first connector when the disk drive unit is inserted in the housing; and a fifth connector arranged in the housing for plug-in connection to the second connector when the printed wiring board is inserted in the housing.
In this magnetic disk module, the connector of the housing is used for plug-in connection of the module to the data storing device body, and at least one disk drive unit or at least one printed wiring board can be easily detached from and attached to the housing by the plug-in connection between the connectors. Therefore, for example, if two sets of disk drive units and printed wiring boards are included in one module, it is possible to detach a disk drive unit or printed wiring board of one set from the module, with the connector of the housing remaining connected to the connector of the data storing device body and the connectors of the disk drive unit and printed wiring board of the other set remaining connected to the connectors of the housing.
In addition, the printed wiring board assembly according to the present invention comprises a first printed wiring board, a second printed wiring board attached to the first printed wiring board, and a bent plate member for mounting the second printed wiring board to the first printed wiring board, the second printed wiring board having an outer surface, and terminals projecting from the outer surface of the additional printed wiring board in the condition where the additional printed board is mounted to the first printed wiring board, the second printed wiring board being fixed to the plate member by screws so that heads of the screws protrude higher than the terminals.
This printed wiring board assembly can be used for the above magnetic disk module or the like. The printed wiring board assembly includes the second printed wiring board attached to the first printed wiring board. The second printed wiring board has terminals projecting from the outer surface thereof. The second printed wiring board is fixed to the plate member by screws, so that heads thereof protrude higher than the terminals. Therefore, when the second printed wiring board is detached from the first printed wiring board and placed on a flat conductor, it is possible to prevent the terminals from contacting the flat conductor and a formation of a short-circuit can be avoided.